News tagged with visible spectrum
Invisibility carpet cloak can hide objects from visible light
(PhysOrg.com) -- Most of the invisibility cloaks that have been demonstrated to date conceal objects at frequencies that are not detectable by the human eye. Designing invisibility cloaks that can conceal ...
Nano-LEDs emit full visible spectrum of light
(PhysOrg.com) -- Physicists from Taiwan have designed and fabricated nano-sized light-emitting diodes (LEDs) that emit light spanning the entire visible spectrum. Although the tiny full-color LEDs aren't intended ...
Novel negative-index metamaterial that responds to visible light designed
A group of scientists led by researchers from the California Institute of Technology has engineered a type of artificial optical material—a metamaterial—with a particular three-dimensional structure such that ...
Apr 22, 2010 |
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A breakthrough for terahertz semiconductor lasers
(PhysOrg.com) -- Potential applications, says an engineering professor, include disease diagnosis and detection of concealed explosives.
Jan 13, 2011 |
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Trapping a rainbow: Researchers slow broadband light waves with nanoplasmonic structures
A team of electrical engineers and chemists at Lehigh University have experimentally verified the "rainbow" trapping effect, demonstrating that plasmonic structures can slow down light waves over a broad range of wavelengths.
Mar 14, 2011 |
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Mantis shrimps could show us the way to a better DVD
(PhysOrg.com) -- The remarkable eyes of a marine crustacean could inspire the next generation of DVD and CD players, according to a new study from the University of Bristol published today in Nature Photonics.
Oct 25, 2009 |
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Berkeley Researchers Light Up White OLEDs
(PhysOrg.com) -- Light-emitting diodes, which employ semiconductors to produce artificial light, could reduce electricity consumption and lighten the impact of greenhouse gas emissions. However, moving this ...
Apr 06, 2010 |
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Trifid triple threat
Smouldering several thousand light-years away in the constellation of Sagittarius (the Archer), the Trifid Nebula presents a compelling portrait of the early stages of a star's life, from gestation to first ...
Aug 26, 2009 |
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Metal oxides hold the key to cheap, green energy
Harnessing the energy of sunlight can be as simple as tuning the optical and electronic properties of metal oxides at the atomic level by making an artificial crystal or super-lattice 'sandwich' says a Binghamton ...
Nanotechnology / Nanomaterials
Apr 19, 2012 |
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Researchers change the color and shape of a single photon
(PhysOrg.com) -- A team of researchers from the CNST and ITL has simultaneously changed the color and shape of a single photon, the smallest unit of light.
Oct 06, 2011 |
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Scientists solve mystery of colorful armchair nanotubes
(PhysOrg.com) -- Rice University researchers have figured out what gives armchair nanotubes their unique bright colors: hydrogen-like objects called excitons.
Nanotechnology / Nanomaterials
Jan 09, 2012 |
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Scientists Build First 'Frequency Comb' To Display Visible 'Teeth'
(PhysOrg.com) -- Finally, an optical frequency comb that visibly lives up to its name. Scientists at the University of Konstanz in Germany and the National Institute of Standards and Technology in the U.S. ...
Oct 29, 2009 |
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Dark matter: Physicists may have found piece of the puzzle
European astronomers said on Wednesday that an anomalous energy signal detected by an orbiting satellite could be a telltale of the enigmatic substance known as dark matter.
Apr 01, 2009 |
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Discovery of an Unexpected Boost for Solar Water-Splitting Cells
(PhysOrg.com) -- A research team from Northeastern University and the National Institute of Standards and Technology has discovered, serendipitously, that a residue of a process used to build arrays of titania ...
Nanotechnology / Nanomaterials
Apr 22, 2009 |
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New 'broadband' cloaking technology simple to manufacture
(PhysOrg.com) -- Researchers have created a new type of invisibility cloak that is simpler than previous designs and works for all colors of the visible spectrum, making it possible to cloak larger objects ...
May 20, 2009 |
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Visible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to 750 nm. In terms of frequency, this corresponds to a band in the vicinity of 790–400 terahertz. A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum (see: luminosity function). The spectrum does not, however, contain all the colors that the human eyes and brain can distinguish. Unsaturated colors such as pink, and purple colors such as magenta are absent, for example, because they can only be made by a mix of multiple wavelengths.
Visible wavelengths also pass through the "optical window," the region of the electromagnetic spectrum that passes largely unattenuated through the Earth's atmosphere. (Blue light scatters more than red light, which is why the sky appears blue.) The human eye's response is defined by subjective testing (see CIE), but atmospheric windows are defined by physical measurement.
The "visible window" is so called because it overlaps the human visible response spectrum. The near infrared (NIR) windows lie just out of human response window, and the Medium Wavelength IR (MWIR) and Long Wavelength or Far Infrared (LWIR or FIR) are far beyond the human response region.
Many species can see wavelengths that fall outside the "visible spectrum". Bees and many other insects can see light in the ultraviolet, which helps them find nectar in flowers. Plant species that depend on insect pollination may owe reproductive success to their appearance in ultraviolet light, rather than how colorful they appear to us. Birds too can see into the ultraviolet (300-400 nm), and some have sex-dependent markings on their plumage, which are only visible in the ultraviolet range.
For more information about Visible spectrum, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.